LOOP AT it_tab INTO st_tab.
**供应商主数据加前导零
CALL FUNCTION 'CONVERSION_EXIT_ALPHA_INPUT'
EXPORTING
input = st_tab-lifnr
IMPORTING
output = st_tab-lifnr.
po_item = po_item + 10.
"采购单表头资料
poheader-purch_org = 'WYPO'. "采购组织
poheader-pur_group = st_tab-ekgrp. "'WY1'. "采购组
poheader-comp_code = 'WY'. "公司代码
poheader-doc_type = st_tab-bsart. " 'NB'. "单据类别
poheader-creat_date = sy-datum. "创建日期
poheader-vendor = st_tab-lifnr. "'0001000000'. "供应商代号
poheader-langu = sy-langu. "语言
poheader-doc_date = sy-datum. "凭证日期
poheaderx-comp_code = 'X'.